1. Technical Field
The present invention relates in general to disk drives and, in particular, to an improved system and apparatus for providing a streamlined contour and reduction in axial flow at the suspension-to-flexure attachment interface in a disk drive.
2. Description of the Related Art
Data access and storage systems generally comprise one or more storage devices that store data on magnetic or optical storage media. For example, a magnetic storage device is known as a direct access storage device (DASD) or a hard disk drive (HDD) and includes one or more disks and a disk controller to manage local operations concerning the disks. The hard disks themselves are usually made of aluminum alloy or a mixture of glass and ceramic, and are covered with a magnetic coating. Typically, one to five disks are stacked vertically on a common spindle that is turned by a disk drive motor at several thousand revolutions per minute (rpm).
A typical HDD uses an actuator assembly to move magnetic read/write heads to the desired location on the rotating disk so as to write information to or read data from that location. Within most HDDs, the magnetic read/write head is mounted on a slider. A slider generally serves to mechanically support the head and any electrical connections between the head and the rest of the disk drive system. The slider is aerodynamically shaped to glide over moving air in order to maintain a uniform distance from the surface of the rotating disk, thereby preventing the head from undesirably-contacting the disk.
A slider is typically formed with an aerodynamic pattern of protrusions on its air bearing surface (ABS) that enables the slider to fly at a constant height close to the disk during operation of the disk drive. A slider is associated with each side of each disk and flies just over the disk's surface. Each slider is mounted on a suspension to form a head gimbal assembly (HGA). The HGA is then attached to a semi-rigid actuator arm that supports the entire head flying unit. Several semi-rigid arms may be combined to form a single movable unit having either a linear bearing or a rotary pivotal bearing system.
The head and arm assembly is linearly or pivotally moved utilizing a magnet/coil structure that is often called a voice coil motor (VCM). The stator of a VCM is mounted to a base plate or casting on which the spindle is also mounted. The base casting with its spindle, actuator VCM, and internal filtration system is then enclosed with a cover and seal assembly to ensure that no contaminants can enter and adversely affect the reliability of the slider flying over the disk. When current is fed to the motor, the VCM develops force or torque that is substantially proportional to the applied current. The arm acceleration is therefore substantially proportional to the magnitude of the current. As the read/write head approaches a desired track, a reverse polarity signal is applied to the actuator, causing the signal to act as a brake, and ideally causing the read/write head to stop and settle directly over the desired track.
In the prior art, airflow-induced vibration of the rotary actuator 11 (see, e.g., FIG. 1) in disk drives adversely affects performance because of track misregistration, or TMR. In a typical design, the conductive traces on the integrated lead suspension (ILS) tail 13 that extend from the head gimbal assembly (HGA) 15 are soldered to the pads 17 on a flexible cable assembly 19. In such an arrangement, the flexible cable assembly pads 19 cumulatively provide a large surface area against which the axial or cross airflow acts at the disk edge boundaries when the actuator 11 rotates toward the inner diameter of the disks. The flexible cable assembly itself is a stiffener that acts not only as a barrier to the circumferential flow resulting in increased torque disturbance, but also exacerbates the axial flow impinging on the ILS tail 13. These forces are transmitted to the actuator arm structure 21 and result in increased vibration of the actuator 11 and manifest as TMR degradation. Thus, a solution that addresses this problem would be desirable.